From the founding of the People's Republic of China to now, after many years of construction and development, China's iron and steel industry has made significant achievements; and meanwhile, the market also imposes increasingly high requirements on quality for the iron and steel industry.
In the continuous casting industry, at the end of casting of a ladle of molten steel, slag floating on the molten steel in the ladle will gradually flow into the tundish. Excessive tundish slag degrades purity of the molten steel, speeds up erosion of the tundish lining, and influences quality of a billet. Thus, it is necessary to control the flowing of the slag from the ladle to the tundish, which is very important for improving the quality of the billet.
In recent years, the technology of reflecting a state of ladle slag by detecting vibration signals of molten steel with slag becomes prevalent internationally.
Reference is made to FIG. 1, which is a structural schematic view of a ladle slag vibration signal detection device in the prior art.
Molten steel in a ladle 01 flows into a tundish 02 via a shroud protective tube 03 to which an operating arm 04 is connected. A vibration signal detection device includes a telescopic pipe 06 and a vibration sensor (not shown) mounted inside a fixing casing 05. The telescopic pipe 06 has a telescopic function, with its telescopic end optionally abutting against the shroud protective tube 03, and its fixed end being connected with the vibration sensor mounted inside the casing 05. When the telescopic end of the telescopic pipe 06 abuts against the shroud protective tube 03, the telescopic pipe 06 serves as a vibration transmission medium to transmit a vibration signal to the vibration sensor at the other end. Since the different proportion of the steel slag to the molten steel causes the different vibration signal of flowing impact, by detecting the variations of this signal, the vibration signal detection device may determine a state of the ladle slag, and further control the slag flowing down from the ladle.
However, in the above ladle slag detection device, only the telescopic end of the telescopic pipe 06 contacts with the vibration source, while the other end transmits vibration wave signals to the vibration sensor. The vibration waves may only be transmitted in one direction from the telescopic end of the telescopic pipe 06 to the vibration sensor at the fixed end of the telescopic pipe 06, and the waves received by the vibration sensor are transverse waves or longitudinal waves with weak vibration signals, thus affecting the true alarm rate of the ladle slag.
Therefore, it is an important technical problem to be solved by those skilled in the art to improve the true alarm rate of a ladle slag.